Don't play this game at 3/4 players if you don't like that aspect. But resigning is a very important part of the rules. TTA without resignation would change the game such that military would be THE dominant way to win, and games could too often be decided by who drew wars earlier.
Basically if there is a very weak opponent at the table who doesn't keep up militarily, why should someone be handed the win because they got the 1st War over Culture and got to launch it at them? It isn't kingmaking to resign, that's part of the rules. The resign mechanic is there to provide a catch up for those players in poor positions as it should encourage you to attack someone who is in contention and not launch it at players who will/should resign if you attack them.
Honestly my complaints usually run the other way--I wish some players would resign. There are some who never will, and do just hand games to players. If I have a war and expect you to resign if I aim it at you, then instead I will and should launch it at whomever the other competitor is (unless I do want to force you out of the game). But sometimes I do that, and then some other player launches the war at the weakling and gets tons of easy culture and that's pretty annoying since the better play would be to resign.
Finally your question is a bit interesting to me anyhow because in general the high culture players should be the ones you want to war anyhow--they have lots of culture that you need to steal in order to beat them and they probably invested more in to culture than military. I'm not sure how you think this always results in wins for the high culture players. (Unless you are at a table of 3 players running high culture and you are the only military player...then sometimes the culture players can still win. In those cases if you only have one War over Culture try saving it for the Age 3 to Age 4 crossover--players cannot resign on their turn if it is Age 4 so you should still be able to get a ton of culture with a well timed war and possibly win.
